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From Rick Hillegas <Richard.Hille...@Sun.COM>
Subject Re: optimizer and left outer joins
Date Mon, 06 Apr 2009 12:54:17 GMT
Mike Matrigali wrote:
> if my multi table query only includes a series of left outer joins, 
> does  this force the optimizer to only choose that order of tables, 
> unlike a regular join where it will consider various orders?
>
> /mikem
>
Hi Mike,

I haven't looked at the code but that's how it should work. The 
left-join operator isn't commutative or even associative, so the join 
order can't be permuted. Jeff was aware of this when he wrote the 
optimizer. Have you run across a nested left join where the join order 
looks suspicious?

Thanks,
-Rick

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